An Overview of Microbial Interactions with Sediment Dynamics

In aquatic environment, microorganisms such as bacteria and microalgae usually secrete a matrix of mucilaginous extracellular polymeric substances (EPS) to form a “microbial biofilm” when they are associated with solid surfaces (e.g., sediment particles, plant surfaces). Biofilms and the associated mucilaginous secretions form a cohesive matrix surrounding sediment particles, modifying the sediment properties, changing the sediment stability, and influencing the sediment dynamics. The purpose of this overview is to examine recent information concerning the roles of microbial interactions with sediment dynamics. The microbial biofilm affects a number of changes on the physico-chemical and biological properties of sediment. These range from the macro-scale stabilization of sediment to the micro-scale bioflocculation of sediment particles. Also microbial biofilms are associated with considerable variability in the properties of natural sediments. Sedimentological factors and biological factors interact in a complex manner within the hydrodynamic regime both on a temporal as well as on a spatial scale.